Exodus 15:3

ה' איש מלחמה means The Lord is a Master of war; just as, (Ruth 1:3) “the איש (i. e. the master) of Naomi”. (Cf. Rashi on that verse). Wherever the words איש and אישך occur they must be translated by בעל; so, too, (1 Kings 2:2) “Be thou strong and show thyself an איש” — a mighty person. ה' שמו THE LORD IS HIS NAME — His wars are not waged with martial weapons but He fights by means of His Name, just as David said, (I Samuel 17:45) “But I come against thee in the name of the Lord of Hosts”. Another explanation of ה׳ שמו — He is a man of war, but His Name is the Lord (the God of Mercy): even at the time when He battles against and avenges Himself upon His enemies He retains His attribute (that expressed by His name ה׳) showing pity to His creatures and feeding all the inhabitants of the world; not as is the nature of the kings of the world each one of whom when he is engaged in war turns aside from all other engagements, and has not the power to do both this and that (cf. Mekhilta).

יְהֹוָ֖ה אִ֣ישׁ מִלְחָמָ֑ה יְהֹוָ֖ה שְׁמֽוֹ׃        

The Lord is a man of war: the Lord is his name.